Java provides a rich library of different data structures to store and perform operations on those data. Java collection framework classes HashMap, LinkedHashMap, TreeMap, and HashTable provides an implementation of Map interface. All these are used as key and value store data structures. The map is the most used collection class after arrays and lists. […]
Categories
In-Memory Local Cache Option for Java
In Java, an in-memory cache can be implemented using ConcurrentMap very efficiently, but it has only the problem that objects can not be evicted automatically after a certain time or limit, we need to remove entries manually. In many situations, the in-memory cache can be very useful to increase speed, but obviously, it will also […]
While working with HTTP clients in java, many times we get a certificate validation exception as given below. Caused by: sun.security.validator.ValidatorException: PKIX path building failed: sun.security.provider.certpath.SunCertPathBuilderException: unable to find valid certification path to requested target The above exception can be caused due to a self-signed certificate or expired certificate as the client is unable to […]
Categories
How to Write MySql Junit Tests?
MySql is the most used open-source RDBMS in the world with different application development stacks. As nowadays most of the development of the system is TDD based, so for writing test cases for the MySql database will require running DB or we can use H2 database with MySql mode or we can even use Embedded […]
While working with Postgres JSONB type and Java, if we assign the value of type UUID as a string then we will get the following exception. To assigning value incorrect way is given below, if you are using PreparedStatement. First, in the query, you need to write input param par as given below for the […]
While working with Postgres UUID type and Java, if we assign the value of type UUID as a string then we will get the following exception. To assigning value incorrect way is given below, if you are using PreparedStatement. If the value of UUID is a string type, then first you need to convert it […]
Postgres is one of the leading open-source RDBMS for developing applications using Java. As now development involves more and more TDD, we need to write Junit tests that can run independently on any build environment without the dependency on any required Database engine. For the Postgres database, I found one very handy Java lib that […]
Categories
How to validate UUID String in Java
Many times we are supposed to get a string and that should be a valid UUID or GUID. Unfortunately Java UUID class don’t provide any function to validate whether a string is valid UUID or not. In many places, you will see to use the UUID java class function fromString, if any exception then the […]
Kafka Streams is a client library that is used to process a stream of messages on a topic and either store it within Kafka or send it to some other Kafka topic. One can check complete documentation of Kafka Streams. In Kafka Stream, I will show with one example, how one can use Spring boot […]
Apache Kafka is open-source and widely used software for event stream platform. It is mainly used for service integration, data integration, creating data pipelines and real-time data analytics, and many. You can get more details from here Apache Kafka. For development, it has libs for almost every development platform. In this post, I am going […]